将MySQL中的日期和时间从不同的列连接到单个列中

为此，使用 CONCAT() 函数将日期和时间连接起来。首先我们先创建一个表 −

mysql> create table DemoTable
   -> (
   -> ShippingDate date,
   -> ShippingTime time,
   -> ShippingDatetime datetime
   -> );
Query OK, 0 rows affected (0.50 sec)

使用 insert 命令向表中插入一些记录 −

mysql> insert into DemoTable(ShippingDate,ShippingTime) values('2019-01-10', '10:40:20');
Query OK, 1 row affected (0.13 sec)

mysql> insert into DemoTable(ShippingDate,ShippingTime) values('2019-06-14', '04:00:10');
Query OK, 1 row affected (0.14 sec)

使用 select 语句显示表中的所有记录 −

mysql> select *from DemoTable;

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输出结果

+--------------+--------------+------------------+
| ShippingDate | ShippingTime | ShippingDatetime |
+--------------+--------------+------------------+
| 2019-01-10   | 10:40:20     | NULL             |
| 2019-06-14   | 04:00:10     | NULL             |
+--------------+--------------+------------------+
2 rows in set (0.00 sec)

以下是将 MySQL 中的日期和时间从不同列连接到单个列中的查询语句 −

mysql> update DemoTable set ShippingDatetime=concat(ShippingDate,' ',ShippingTime);
Query OK, 2 rows affected (0.11 sec)
Rows matched: 2 Changed: 2 Warnings: 0

让我们再次检查表记录 −

mysql> select *from DemoTable;

输出结果

+--------------+--------------+---------------------+
| ShippingDate | ShippingTime | ShippingDatetime    |
+--------------+--------------+---------------------+
| 2019-01-10   | 10:40:20     | 2019-01-10 10:40:20 |
| 2019-06-14   | 04:00:10     | 2019-06-14 04:00:10 |
+--------------+--------------+---------------------+
2 rows in set (0.00 sec)